Fuse.



, A. F. BAUM.

FUSE.

APPLICATION FILED MAB. 24, 191s. RBNEWBD rma. 24, 1914. A

.l 1,102,981, Patented July 7, 1914.

ALBERT F. DAUM, 0F PITTSBURGH, PENNSYLVANIA.

FUSE.

Specification of Letters Patent.

Patenteaauly 7,1914..

Continuation in part of appIication Serial No. 702,599, led .Tune 8,' 1912.v This application filed March 24, 1913, Serial No. 756,544. Renewed February 24, 1914. Serial No. 820,662.

To all whom 'it may concern Be it .known that I, ALBERT F. DAUM, a citizen of the United States, and residing at Pittsburgh, in the county of Allegheny and lState of Pennsylvania, have invented certain new and useful Improvements in Fuses, of which the following is a specification.

My invention relates to improvements in fuses, and has for its object to provide a construction by means of which the fuse element is prevented from being cut-oil' at its point of exit from the end plugs or other support; to provide a structure in which the contact with the end cap is made in the form of a wiping contact; to provide a structure in whlch the support may be yieldable; and to provide a construction which 1s simple -and eiicient in' operation, durable in construction, and which can be made at a relatively'low cost.

To these andother ends, the nature of which will be readily understood as the invention is hereinafter disclosed, said invention consists in the improved construction and combination ofparts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims.

In the drawings, in which similar reference characters indicate similar parts in each of the views :-Figure 1 is a longitudinal sectional view of a portion of a refillable fuse showing one way in which my present 'invention may be applied. Figs.

2, 3, 4, 5, 6, and 8 are similar views showing various modifications of the invention. Fig. 7 is aI face view showing a preferred form of support where the fuse element is in the form of a strip, this form of support being shown in connection with Fig. 6. Figs. 9 and 10 are detail views of a resilient support for the fuse element. Fig. 11 is an end view of the form shown in Fig. 1 with the end cap removed.

One of the essential features for eiciency in a fuse and especially in reillable fuses, is the provision of a good contact between the fuse element and the end cap, and my experience has shown that to secure the best eiciency, this contact should be provided by wiping the end cap over the fuse element. Where, however, as in refillable fuses, the en d cap is threaded on to the ber shell, the giving of this wiping contact has the effect of iiattening the fuse element itself, and where the fuse element is of small cross section, such, for instance, as is provided in telephone fuses or fuses necessitating the use of fuse wire of substantially the small'- est gage, this flattening becomes a serious factor, by reason of the liability of practically cutting off this wire at its point of exit from the supporting member through which it extends, the flattening of the wire beyond that point not materially affecting the conducting qualities, since the cross-sectional area of the wire will remain but in a different form.

My present invention provides for practically insuring `against cutting wire at this point by increasing the ydistancebetween the opposing members between -Which the element is carried after passing beyond the ber, this increase being .provided in any suitable manner, butpreferably by flaring the end plug or member so as to increase the distance in the vicinity of the opening to which the fuse element extends. In the drawings, I have shown various forms of such end members. For instance in Fig.A 1, this end member, indicated at 10, is in the form of a washer whichabuts against the end of the shell of insulating material 11. In use, the washer is slightly dish-shaped, the drawings illustratin the amount of depression for a large-size fuse wire. It will be understood that where the fuse wire is of relatively small gage, the amount of depression will be relatively smaller.

As will be readily understood, the threading of the end cap 12 on to the shell 11, will cause the fuse element, indicated at 13, to be Iiattened when the threadin has caused pressure to be applied on the use wire. By reason of the particular shape, this Hatten- .ing will take place iirst adjacent the outer periphery of the washer, and as the pressure isincreased, this flattening will be gradually carried toward the center of the washer, but as will be readily understood, a movement of the end cap sufficient to cause the `outer edge of the washer to contact withthe end cap will still leave a distance between the wash face at the center of the washer and the end cap, which distance `will not be decreased by any additional pressure that may be placed on the end cap, so that there will always remain a cross-section thickness equal to this distance. There are several particular advantages due to this particular arrangement; for instance, the flattening effect is provided from the point of greatest distance from the center, always leaving the greatest amount of fuse metal at the center and in position -to insure a positive contact with the cap; another advantage lies in the fact thatvshould the end cap be threaded to provide a contact with the lwasher, the metallic contact thus provided is in a thin line adjacent the peripherv of the end cap and removed from the point where the fusible metal is located, thereby greatly 'decreasing' any possibility of a fusing of the washer to the end cap, and since the end cap is preferably provided with openings, the heat generatedl in the blowing of the fuse will quickly dissipate without providing a fusing of the cap and er. '.[he end plugs may be of any desired ty e the washer form shown in Fig. l being plrje ferred owing to its relative inexpensive cost .of manufacture. The other forms of lsuch plugs or supports are shown in Figs. 3, 4, and 5, these plu or sup orts extending into the ber shell, Fig. 3 s owing the member 10 as having a smooth eripheral face,'while Fig. 4 shows a somew at similar structure with the plug threaded to the shell; Fig. 5 shows a modification in the shape of a lug by means of which it may be made sliglhtly resilient so as to provide for the expansion V and contraction ofthe shell without affecting the fuse contact with the end cap, the slight resiliency of themember producing this ell'ect. -In Fig. 6, I have shown a somewhat similar arrangement of support where the fuse element is in the form of a. strip, the support 10 in this instance, preferably having lateral groove like depressions into which the fuse element is bent, as in rig. 6, thus providing a depressed portion or portions acting .similar to that referred to in connection with Fig. 1, the flattening of which is indicated somewhat in Fig. 11.' I may also provide a resilient support, either bythe use ofa spring member 14 between the end of the shelland the washer 10, the latter having the dish-shaped feature, or I may form the spring member itself with a .ish-shaped end, as-shown in Fig. 10, in

which case the member will form the .su

port, the washer being dispensed with. each of these forms however, the outer face is formed dish-shaped lor depressed about the point of exit of the fuse element producing a substantially similar ellect to that produced by the washer of Fig. 1.

An alternative. form of construction 1s illustrated in Fig. 2- in which the end .cap has its inner face dish-shaped to provide for a somewhatsimilar operation, the member 10 in such case having eithera straight face or a dish-shaped face.

lVhile I have herein shown anddescribed several ways in which my invention may be carried into effect, it 'w1ll`be readily understood that changes and modifications therein may be required or deslred in use, and I y pressed in the accompanying claims.

Having thus described my invention, what I claim as new is f l. In afuse, a shell, a member through which the fuse element extends, and an end cap adapted to contact with the element, said cap and member having opposing element-contacting faces relatively shaped to provide an increase of distance therebetweenv at the point of exit of the element from said member, whereby relative movement of the end cap and member to provide a wiping contact will be least effectivey to change `the cross-sectional varea and form of the element at such point of exit.

2. In a fuse, a shell,y a member through -which the fuse element extends, an end ca adapted to contact with the element, sai cap and memberv havin Aopposing elementcontacting faces relative y shaped to provide l i an increase of distance therebetween at the point of exit of the element from said member, whereby relative movement of the end cap and member to rovide a wiping contact will be least e ective to change the cross-sectionalarea and form of the fuse element at such point of exit, said distance in# crease being gradual from a point approximating the periphery of the member.

3. In a fuse, a shell, a member havin a substantially central opening through which the fuse element is adapted to extend, and an end cap adapted to contact with the fuse element, said member having a face de` pressed at the point of element exit, said end cap having its inner face shaped to cooperate with the depressed face of said member to provide a space between said faces at and decreasing in depth away from the point of exit of the element.

4. In a fuse, a shell, a member having a substantially central openin through which the point' of exit of the element,A said mem- 1o the fuse element is adapte to extend,`and ber including a yieldable su port.

an end cap adapted to contact with the fuse In testimony whereof I a my signature elemeit, saill member fhalving a 'face de in presence of two witnesses.

presse at t e point o e ement exit, sai

end cap having its inner face shaped to co- ALBERT F' DAUM operate with the depressed face of said member to provide a space between said faces at and decreasing in depth away from Witnesses:

L. H. MCCABE, Cuna W. HELTMAN.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents; i

Washington, D. C. 

